Drive mechanism for flap-carrying drums



May 6, 1958 M. C. GLEE RUP-MCLLER DRIVE MECHANISM FOR FLAP-CARRYING DRUMS Filed Sept. 23, 1952 FRIDAY 2,833,067 Patented May 6, 1958 DRIVE MECHANEM FGR FLAP-(ZARRYING DRUMS Magdalin Christian Gieerup-Miiller, Copenhagen, Denmark Appiication Eiepternber 23, 1952, Serial No. 310,999

Ciaims priority, application Denmark November 6, 1951 3 Claims. (Cl. 40-111) The invention relates to a drive mechanism for flapcarrying drums of the kind used for the display of changing symbols, particularly figures, in instruments and apparatus, particularly clocks, date indicators, automatic perpetual calendars, calculating machines, cash registers and similar apparatus for displaying figures or other indicia. Such flap-carrying drums comprise a set of flaps connected to the drum for independent movement about regularly arranged individual pivotal axes which are equidistant from and parallel to the axis of the drum, each flap being provided on one or both sides with symbols which successively become visible by the rotation of the drum past a flap-holder which holds a particular single flap or a combination of two adjacent sides of two adjacent flaps in a position suitable for display. The advantage of using such flap-carrying drums instead of ordinary cylindrical figure drums is that if it is desired to have the drum selectively display a large number of different figures, for instance 31 in the case of a date indicator, only a small fraction of the surface of the cylindrical drum will be available for each individual figure, so that the figures must either be very small or a very large drum is required with respect to the degree of legibility which is obtained.

Most flap-carrying drums of known construction are rotated by driving means connected to the drum axle. When the drum is carrying a large number of flaps it must be capable of being turned through asmall angular displacement or an integral multiple thereof with sufficient accuracy to ensure that a given flap will be turned into visible position, and it is therefore necessary for the turning of the drum to provide a drive mechanism with subdivisions as accurate as those of the drum. This will require either the use of costly high precision drive mechanisms or large driving wheels of accurate pitch, which will make the whole mechanism cumbersome.

It is the object of the present invention to provide a simple and inexpensive drive mechanism for such flapcarrying drums, which mechanism will provide the required high degree of accuracy in the stepwise advance of the drum even if the latter holds a large number of flaps. The invention thus makes it possible to use drive mechanisms of coarse construction and Without precision dimensional tolerances which nevertheless will be fully reliable and suitable for use, even in precision apparatus.

According to the invention this object is achieved by the use of a stop member placed outside the drum in the path of travel of the flaps and against which the flaps will be successively pressed so that they will be firmly held with the free edge of a single flap accessible, and of a movable actuator placed close to the supporting member and arranged to impinge in the course of its motion against the free edge of the flap held by the supporting member and thus advance the flap and thereby the entire drum one step, and the result is thereby achieved that the actuator may act on the flaps at the relatively wide spacing or pitch between'thcir outer edges, a pitch which is considerably greater than that at the periphery of the drum.

In the drawing:

Fig. 1 shows a combined calendar and clock including a flap-carrying drum in front elevation,

Fig. 2 a flap-carrying drum in side elevation,

Fig. 3 the same drum in front elevation,

Fig. 4 another flap-drum in side elevation,

Fig. 5 a fragment of a flap-drum on an enlarged scale in side elevation, and

Fig. 6 a third flap-drum in side elevation.

The calendar shown in Fig. 1 consists of a casing 1, in which are placed a day-drum 2, a month-drum 3, an hour-drum 4, a minute-drum 5, and a date-drum 6, which in order to be able to display large figures Within a constricted space is constructed in the form of a flapcarrying drum. The fronts of the drums are visible through windows in the casing 1', and drums are driven in a manner irrelevant to the present invention by a common clockwork or so that the clockwork drives only the hour and minute-drums, the other drums being set by hand at appropriate intervals.

The flap-carrying drum 6 of Fig. 1 is shown in Figs. 2 and 3. The drum 6 comprises a freely revoluble drum axle 7 on which there are fixed two end discs 8. Adjacent to the periphery of each of the discs 8 there'is a circularly arranged series of uniformly spaced holes 9 concentric with the rotational axis of the drum axle 7. The holes 9 in the two discs 8 are in axial alignment. In each pair of aligned holes 9, there is freely rotatably received a pair of laterally extending ears or projections 10. integrally formed with a flap 11. Each flap 11 is thus connected to the drum by the cars 10 which define an individual pivotal axis for each flap 11, this pivotal axis being parallel to the rotational axis of the drum. These pivotal axes of the flaps 11 are all equidistant from the drum axis provided by the freely revoluble axle 7. To hold the flaps in such a position that two normally adjacent flap surfaces will be simultaneously visible through the window of the casing 11, in which the drum 6 is mounted, a supporting member 12 is provided outside the drum. The fiaps advance one by one past the supporting member 12 when the drum is rotated in the direction indicated by arrow 13 in Fig. 2. In the embodiment shown in Fig. 2, use is also made of a springloaded pawl 14, which engages the outer end of successive flaps and thereby urges the drum in a clockwise direction. The upstanding displayed flap 111 is thus urged upwardly so that its free edge presses against an inwardly projecting stop member 18 carried by the supporting member 12. The pawl 14 and stop member 18 thus cooperate to hold the drum in a definite position after each advance.

According to the invention, the drum is advanced one flap at a time by means of an actuator 151 carried at the free end of an arm 15. The arm 15 is located above and behind the supporting member 12 and is mounted on a shaft 16 (Fig. 3) for oscillatory angular displacement in the directions indicated by the double headed arrow 1'7. The actuator 151 thus moves in a vertical plane just behind the stop member 18.

As shown in Fig. 2, the supporting member 12 is engageable by the foremost or upper displayed flap 111.

The stop member 18 holds the next flap to be displayed, 112, with its top edge accessible and presented for engagement by the actuator 151 upon its next downward movement. When this occurs, the top edge of the flap 112 is engaged in the notch in the bottom edge of the actuator 151 and the top edge of the flap is carried past the stop member 18. The flap 112 is sufficiently stiff or rigid to rotate the drum 6 as the flap 112 is forced downwardly by the actuator 115. At the same time that flap 112 is forced downwardly, the foremost or displayed flap 111 also moves downwardly and as soon as its top edge clears thesupporting member 12, it swings downwardly by gravity, initially aided by the springiness of the flap, into the position of the depending flap 113 of which one side is also being displayed. The spring pressed pawl 14 permits the next flap to advance and this flap then assumes a position just behind the flap 112 which is engaged below its top edge by the stop member 18. The pawl 14 also serves as a check against overtravel.

When the actuator 115 moves upwardly, the flap formerly in the position assumed by flap 112 has now moved to the position of the flap 111. Downward swinging movement of the flap 111 cannot occur until after its top edge has cleared the bottom edge of the supporting member 12. However, as-previously described, the pawl 14- presses the top edge of the upper displayed flap 111 into engagement with the under side of the stop member 18. The stop member 18 thus not only prevents reverse rotation of the drum 6 but also positively positions the drum after each advance.

in the embodiment of Fig. 4, the stop member is not generally unitary as in Pig. 2. There is a horizontally reciprocable slide member 152 having an upper surface 121 which engages the bottom edges of the flaps. The slide member 152. has an otiset jog formed therein which provides a downwardly sloping surface 153. In this embodiment, the sloping surface 153 serves as the actuator. Positive engagement between the actuator and the outer edge of the flap, which in this case is its lower edge, provided by the corner formed between the sloping surface 153 and the .leftwardly extending lower portion of the slide member 152. Upon leftward movement of the slide member 152,, the flap, the outer edge of which is engaged by the lower end of the sloping surface 153, will be displaced leftwardly causing clockwise rotation of the drum. Upon movement toward the right, the flap of which the outer edge is nearest to the top of the sloping surface 153' will be allowed to move into the position in which it will be acted upon by the bottom of the sloping surface 153 at the next leftward movement of the slide member 152.

Reverse rotation of the drum is prevented by a serrated member 131 having sloping teeth 1?. The outer edges of the 11 may slide freely over the teeth 19 when the drum is advanced in the forward or clockwise direction. However, when an a' empt is made to rotate the drum backwards, the teeth 1? enga e the outer edges of flaps and prevent such rotation.

The modification of Fig. 6 is generally similar to the arrangement described above in connection with Fig. 4. in Fig. 0, however, the table with its offset jog remains stationary. A star wheel 154 is located below the table 122, The table is slotted so that the teeth 155 of star wheel project upwardly above the surface of the table 122 where the teeth individually engage ill;- outcr c sea of the flaps as the outer edges slide leftwardly toss the table This arrangement pen mits the indicator to be advanced by a single flap by an angular displacement of one-ninth of a revolution in the case oi a nine point star wheel as shown in 6. This corresponds to an angular displacement of 40 degrees which is easily obtainable in practice.

it will be appreciated that various modifications may be made in the illustrati e embodiments of the invention .L which have been disclosed without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A display device of the class described, comprising: a revoluble drum; a uniform series of flat and effectively rigid flap-like indicia bearing display members each having an inner portion pivoted to said drum and a free outer edge portion, the pivotal axes of said inner portions extending parallel to the rotational axis of said drum in regularly spaced relationship at equal distances from said drum axis; a stop member disposed exteriorly of said drum in the path of travel of said display members during rotation of said drum, said stop member maintaining the free outer edge portion of a single display member which is in engagement therewith accessible independently of all other display members; an actuating member displaceable for individual engagement with said outer edge portion of said single display member, actuating movement of said actuating member exerting a force on the outer edge portion of said single display member, said force being directed toward the pivoted inner portion of said single display member, said single display member being held so positioned by engagement with said stop member that saidvforce will have at least a component directed tangentially with respect to said drum, said force causing angular displacement of said drum accompanied by movement of all of said display members, the travel of said actuating member at each actuation thereof being of magnitude sufficient to move said single display member past and out of engagement with said stop member and through a distance suflicient to clear said stop member and allow the next succeeding display member to engage said stop member with its free outer edge portion positioned for subsequent engagement by said actuating member; and means for preventing rotation of said drum in the direction opposite to that produced by said actuating member.

2. A display device according to claim 1, wherein said drum is freely revoluble and in which said means for preventing rotation of said drum comprises means engageable by and acting on the outer edge of at least one of said display members.

3. A display device of the class described, comprising: a freely revoluble shaft; a pair of axially spaced disc members fixed to said shaft; a uniform series of flap-like flat and effectively rigid yet inherently springy indicia bearing display members each having an inner portion extending between said disc members and a freeouter edge portion, said inner portions of all of said display members being pivotally connected to both of said disc members for movement about regularly arranged pivotal axes disposed at equal distances from the rotational axis of said shaft; a stop member located substantially directly above a position successively assumed by each of said pivotal axes as each axis moves downwardly during revolution of said disc members, said stop member being engageable by successive ones of said display members for holding a single one of said display members with its outer edge portion disposed above its pivotal axis and with the outer edge portion of said single display member individually ac cessible independently of the outer edge portions of all others of said display members; a vertically reciprocable actuating member disposed above said free edge portion of said single display member, said actuating member being engageable upon downward movement thereof with the outer edge portion of said single display member to force said edge portion downwardly past said stop member accompanied by an angular displacement of said disc members entraining all others of said display members, said angular displacement bringing the next succeeding one of said display members into the position previously occupied by said single display member after subsequent upward movement of said actuating member; a supporting member engageable with the display member which has just passed said stop member for holding the display rnem- 5 6 her upright with its outer edge positioned below said stop References Cited in the file of this patent member and with one side of said display member ex- UNITED STATES PATENTS hibited to view; and resilient means acting on at least one of said display members for urging the outer edge of the 428,423 Snyder May 20, 1890 display member which is in engagement with said sup- 5 584,700 off et a1 June 1897 porting member upwardly against said stop member for 2,714 Casler June 26, 1900 bringing said single display member into a predetermined 1,704,022 Smith Mar. 5, 1929 reference position with respect to said stop member after 2,458,657 Torrence Jan. 11, 1949 each actuation of said actuating member. 2,561,790 Elms July 24, 1951 

